The present invention relates to a control system for a controlled body, such as a robot manipulator.
Laid-open Japanese patent application No. 58-169203 discloses a control system for a robot where the optimum feedback gain values are stored, each for position assumed by a robot and load applied to the robot. In this conventional control system, a feedback gain provided when the load is applied is different from a feedback gain provided when no load is applied to the robot even with the same position assumed by the robot.
If this conventional control system is implemented in a controller for a multi-articulation robot manipulator using an electric motor as an actuator for driving each of the articulations, since the feedback gain is selected from the initially set fixed stored values even if there occur variation in friction at each of the articulations which is caused by environment temperature/humidity and aging of the mechanical parts, a problem arises that the motor is controlled with the motor driving electric current saturated or with most of the motor power potential left unconsumed, failing to assure the complete stability in motion and failing to accomplish speed-up of the motion.